A standard drawer slide has as described in U.S. Pat. No. 6,386,659 an outer rail forming a plurality of parallel and inwardly open tracks, an inner rail fitting in the outer rail and having a plurality of flat surfaces each confronting and extending parallel to a respective one of the tracks, and a respective row of balls in each of the tracks and riding on the respective inner-rail surface. Normally each of the flat surfaces is perpendicular to a bisector of the respective track corner. Such a slide is used in many different applications, for instance to support a drawer in a piece of furniture or in a vehicle, to carry a shelf usable to support an appliance or as a work surface, or even to carry a seat in a motor vehicle.
This arrangement is highly effective. One of the rails is normally secured to a fixed support and the other to the slidable part—drawer, seat, or the like—such that, when the movable rail moves through its stroke, the balls travel through half this stroke.
The slide is therefore typically formed of four different parts, the two rails, the balls, and the cages that hold the balls at a predetermined spacing from each other. The main expense of manufacture is in the production of the two complexly profiled rails. Each must be made in its own machine having specially configured rollers or dies to produce the two different profiles needed for the interfitting rails.